Production of vane units for spray nozzles



Sept. 1, 1964 F. w. WAHLIN PRODUCTION OF VANE UNITS FOR SPRAY NOZZLES 3Sheets-Sheet 1 Original Filed May 17, 1962 Sept. 1, 1964 F. w. WAHLINPRODUCTION OF VANE UNITS FOR SPRAY NOZZLES 3 Sheets-Sheet 2 OriginalFiled May 17, 1962 SIDE A Sept. 1, 1964 F. w. WAHLIN 3,146,674

PRODUCTION OF VANE UNITS FOR SPRAY NOZZLES Original Filed May 17. 1962 vs Sheets-Sheet s i i P i i H 9 $411" I ll venfor 98 fled llflgaz w g\WIBM United States Patent 3,146,674 PRODUCTION OF VANE UNITS FOR SPRAYNOZZLES Fred W. Wahlin, St. Charles, Iil., assignor to Spraying SystemsCo., a corporation of Illinois Original application May 17, 1962, Ser.No. 195,550, now Patent No. 3,104,829, dated Sept. 24, 1963. Divided andthis application Nov. 26, 1962, Ser. No. 256,783 11 Claims. (Cl. 90-11)This invention relates to vane units of the kind employed in solid conespray nozzles to produce swirling movement and turbulence in the liquidas it advances toward the discharge orifice of the nozzle.

A vane unit of the general kind to which the present invention relatesis shown in my prior Patent No. 2,305,210, patented December 15, 1942,and such vane units have been employed with great success in nozzles ofvarying sizes and designs. In use such a vane unit is located in a fixedposition in the internal chamber of a spray nozzle with the longitudinalaxis of the vane unit coinciding with the central axis of the nozzleorifice, and in order to assure uniformity of whirling motion anduniformity of turbulence in the water or other liquid as it passes fromthe vane unit to the nozzle orifice, it is necessary that the variousvane surfaces be accurately formed and related to each other. It haslong been recognized that excessive and objectionable costs wereinvolved in producing and handling such vane units, in initiallymounting the vane units in the nozzles, and thereafter in removing andreplacing the vane units for cleaning or other purposes, and withparticular relation to cost of manufacture of the vane units, one of themost important factors has been the care required in attaininguniformity and accuracy of form and relationship in the various surfacesof the vane unit.

In view of the foregoing it is the primary object of the presentinvention to provide a new and improved vane unit of the aforesaidcharacter that may be handled and mounted in a simple and convenientmanner, and which, by reason of its novel characteristics of shape andform, may be produced with greater accuracy and at a less cost thanprior vane units of this general kind.

More specifically it is an object of this invention to provide a simpleand effective method for producing vane units of the aforesaidcharacter, and objects related to the I foregoing are to enable all ofthe critical liquid-directing surfaces of such vane units to be formedand finished while the work piece remains in its original relation to awork holder; to enable the vane units to be made from continuous andrelatively long lengths of rod stock; to provide such a rod withpreformed locating surfaces for axially located and advancing such rodstock; and to provide these locating surfaces in a form and relationsuch that portions of the locating surfaces function in impartingcertain desirable characteristics of form in the completed vane units.

Other and further objects of the present invention will be apparent fromthe following description and claims, and are illustrated in theaccompanying drawings, which, by way of illustration, show a preferredembodiment of the present invention and the principles thereof, and whatis now considered to be the best mode in which to apply theseprinciples. Other embodiments of the invention embodying the same orequivalent principles may be used and structural changes may be made asdesired by those skilled in the art Without departing from theinvention.

In the drawings:

FIG. 1 is a vertical sectional view of a spray nozzle utilizing the vaneunit of the present invention;

FIG. 2 is a side elevational view showing vane units;

FIG. 2A is a view similar to FIG. 2 and showing a different embodimentof the vane unit;

3,146,674 Patented Sept. 1, 1964 FIG. 3 is a side elevational view takenfrom the line 3-3 of FIG. 2;

FIG. 4 is a bottom plan view of the structure shown in FIG. 2;

FIG. 5 is a top plan view of the structure shown in FIG. 3;

FIGS. 6, 7 and 8 are views showing the successive steps that areutilized in making the vane unit of FIG. 2;

FIG. 9 is a cross sectional view taken substantially along the line 99of FIG. 8;

FIG. 10 is a schematic vertical elevation showing the milling machinesetup utilized in making the vane unit;

FIG. 11 is a plan view of the structure shown in FIG. 10; and

FIG. 12 is an enlarged schematic portion of FIG. 10 illustrating furtherdetails of the method of making the vane unit.

For purposes of disclosure the invention is herein illustrated asembodied in a vane unit 21 that is adapted for use in a full cone spraynozzle such as the nozzle 22 shown in FIG. 1. The nozzle 22 is but oneof many specific forms of nozzle in which the vane unit 21 may be used,and the nozzle 22 has herein shown comprises a main body 23 with asleeve-like connecting body 24 threaded on its lower end. The main body23 has central passage 25 tapered at its upper end at 26 to a smallerdiameter discharge orifice 27 that is of cylindrical form. The orifice27, the passage 25 and the intermediate tapered portion 26 are centeredon a common axis 28, and within the lower end portion of the passage 25,the vane unit 21 is mounted in a fixed position with its longitudinalaxis coinciding with the axis 28. The function of the vane unit 21 is toimpart swirling movement to water or other liquid passing through thevane unit 21 toward the orifice 27 while at the same time impartingturbulence to the liquid so that the liquid will be discharged from theorifice 27 as a solid or full cone spray rather than as a hollow conespray. Actually the resulting spray is modified in the nozzle shownherein, and in my aforesaid patent, so that as the liquid dischargesfrom the orifice it assumes a non-circular spray pattern, but this isindependent of the present invention, and so far as the presentinvention may be concerned the ultimate spray pattern may be square orround as may be desired. Such modifications of the spray pattern areattained by known means such as the end grooves 23G which produce asquare spray pattern.

The vane unit 21 is shown at an enlarged scale and in considerabledetail in FIGS. 2 to 5, and considered in general, has the parts orelements thereof defined in part by a number of the surfaces that fallin or constitute parts of a cylindrical surface so that the vane unit 21has a longitudinal center line 31 indicated in FIGS. 2 and 3, and in endelevation has a cylindrical or circular outline as will be evident inFIGS. 4 and 5. This general form enables the vane unit 21 to be insertedendwise and with a sliding fit or afirm frictional fit, as desired, intothe central passage 25 of a nozzle as shown in FIG. 1, with thelongitudinal centerline 31 of the vane unit coinciding with the axis 28of the nozzle.

Within the confines of this overall cylindrical boundary, the vane unit21 has a pair of oppositely sloping vanes 35A and 35B which, in endelevation, appear to be semicircular as shown in FIGS. 4 and 5, andwhich are disposed on opposite sides of a center plane 36 that has beenindicated in FIG. 5. This center plane 36 of course passes through theaxis 31, and the vanes 35A and 35B are integrally joined at theirmidpoints and are precise duplicates except that they are reversed as toslope and as to some other physical features as will hereinafter becomeapparent. Because of this duplication, the parts of the vane unit 21 onopposite sides of the center plane 36 will be identified by the samereference characters with the sufiix A or B added, and reference will bemade to side A or side B of the unit as these portions or sides aredisposed on opposite sides of the plane 36, as indicated in FIGS. 3, 4and 5 of the drawings. The adjacent lower sides of the vanes 35A and35B, below their connected midportions, are joined by a wall-like tab 38through which the center plane 36 passes so that the parts of the tab 38lie on both sides of the plane 36, and this tab 38 projectssubstantially below the lower portions of the vanes 35A and 35B and hasa special tapered form that facilitates handling, mounting anddismounting of the vane unit 21 as will be described.

The vanes 35A and 35B are disposed at identical angles to the axis 31,and this angle is preferably about 54 as indicated in FIG. 2, and in thefollowing description, the various surfaces of the vane 35A will bedescribe specifically and corresponding surfaces of the vane 3513 willbe identified in each instance by the same reference character with thesuffix B instead of the sufhx A.

The vane 35A has fiat or planar top and bottom surfaces 41A and 42A thatare parallel and disposed at the aforesaid angle with respect to theaxis 31 and which are perpendicular to the central plane 36. Theoutermost edges of the top and bottom surfaces 41A and 42A are connectedprimarily by a curved surface 43A that forms part of a cylindricalsurface centered on the longitudinal axis 31 of the vane unit 21; and atthe central plane 36, the middle portions of the vanes 35A and 35B areintegrally joined in a diamond shaped area centered on a locating point44 in the plane 36 as shown in FIG. 2. Below the aforesaid diamondshaped area the edges of the vanes 35A and 35B adjacent the center plane36 are integrally connected to the tapered portions of the tab 33.

Above the aforesaid diamond shaped area the vane 35A has a flat surface45A that lies in the plane 36, such surface 45A extending from theextreme end of the vane 35A for about half the distance to the aforesaiddiamond shaped area, and the lower edge of the surface 45A is definedand terminated by -a transverse groove 46A formed in the vane 35A. Thetransverse groove 46A extends parallel to the vane 35B, and is definedby a flat bottom surface 146A that is parallel to the surface 45A, aside surface 246A that constitutes a planar continuation of the surface41B of the other vane 35B, and an opposite planar side surface 346A thatis parallel to the surfaces 413 and 246B.

At the upper extremity of the vane 35A, where the intersection of thesurfaces 41A, 43A and 45A, would otherwise form an extremely sharpcorner, the vane 35A has a rounded surface 47A, and as will becomeapparent this surface 47A, and the corresponding rounded surface 4713 onthe vane 35B, are parts of a common surface of revolution centered onthe longitudinal axis 31 of the vane unit 21. Similarly, in the vaneunit 21 shown in FIGS. 2 to 5, the lowermost portions of the vanes 35Aand 35B have rounded surfaces 48A and 488 formed thereon. Here again,the surfaces 48A and 48B constitute parts of a common surface ofrevolution centered on the axis 31. It should be noted at this point,however, that in the smaller sizes of vane units, where it is desirableto have the longitudinal extent of the tab 38 relatively large inrelation to the diameter of the vane unit, the rounded surfaces 48A and48B are not provided at the lower ends of the vanes 35A and 35B as willbe explained. Such a smaller vane unit 521 as shown in FIG. 2A at asmall scale but comparison of FIGS. 2 and 2A shows that the unit 521 hasa relatively long tab 538 as compared with the tab 38 of FIG. 2. Such alonger tab 538 may be provided readily under the present method ofproduction of the vane units, as will become apparent.

The downwardly projecting tab 38 is defined by a series of intersectingsurfaces some of which are planar and others of which constituteportions of conical surfaces. Thus, the tab 38, when viewed in elevationas shown in FIG. 2, tapers downwardly to a point located on thelongitudinal axis 31 of the vane unit 21, and this tapered form isdefined by a pair of planar surfaces 38A and 3813. The surface 38A isparallel to the surfaces 41A and 42A, while the surface 38B is parallelto the surfaces 41B and 42B.

The opposite sides of the tab 38 are defined by parts of conicalsurfaces that are identical but oppositely related. Thus the side of thetab 38 that is located below the vane 35A is defined by such a surface133A, while the side of the tab 38 that is located below the vane 35B isprovided by such a surface 1388. The surface 138B intersects the surface428 with an included angle of approximately 87, as will be evident inFIG. 9, and to facilitate description this intersection is defined inFIG. 3 as a curved line 50B While the intersection of the conicalsurface 138B with the planar surface 38B is defined by a curved edge orline 518 as indicated in FIG. 3. Further, the conical surface 138Bintersects the surface 41A, as a straight line 523, and at the edge ofthe surface 138B that is defined by the line 528, the arcuate line 538intersects the surface 41A at substantially the center plane as. Thearcuate line 538, as it extends across the tab 38, diverges from theplane 36, as will be evident in FIGS. 3 and 4, and since the lines 50Aand 52B diverge in opposite directions from the plane 36, as will beevident in FIG. 4, the tab 38 has substantial thickness in the areaswhere it is connected to the vanes 35A and 35B. This thickness isrepresented by the distance between dotted lines 53A and 50B in FIG. 4,and it will be noted that this thickness is less in the center portionsof the tab 38 than at the edges thereof.

In contrast to the reduced thickness of the upper central portions ofthe tab 38, it will be observed in FIGS. 3 and 4 that the lower portionsof the tab 38 become progressively thicker toward the lower centralportions of the tab. This results from the use of an angle that is lessthan 90 between the surfaces 42B and 138B, and between the surfaces 42Aand 138A.

The vane unit 21, as thus described, and as shown in FIGS. 1 to 5, maybe produced rapidly, accurately and economically according to thepresent invention by a novel and advantageous method in which theindividual vane units 21 are cut one by one from rod stock such as theelongated rod 91 shown in FIGS. 6 to 8 and 11. The rod 91 has a diametercorresponding to the diameter of the surfaces 43A and 43B, and may be ofrelatively long length so that a large number of vane units 21 may beproduced therefrom. The rod 91 has a plurality of annular grooves 92formed thereabout at spaced intervals longitudinally of the rod, andthese grooves have sloping side walls 147 and 148 and a cylindricalbottom wall 92C. The sloping walls 147 and 148 of adjacent grooves 92are spaced apart in such a distance that in a finished vane unit 21,parts of the walls or surfaces 147 and 148 may provide the surfaces 47and 48 of the finished vane units 21. The width of the bottom wall 92Cof the groove 92 is then made such that the spacing of the grooves 92constitutes a measure of the length of rod 91 required to produce onevane unit 21. The grooves 92 may thus serve as locating means inadvancing the rod 91 and holding the same in the desired longitudinalposition during the forming or machining operations, as will bedescribed.

The units 21 are produced by a series of milling operations that may beaccomplished with a milling machine set-up of the kind shown in FIGS. 10to 12 of the drawings. Thus, a pair of laterally spaced horizontalspindles 95 and 96 extend in parallel relation over and in perpendicularrelation to the path of reciprocation of a worksupporting table 97; andon the table 97 an indexing fixture 98 having a through-chuck 99 andlongitudinal positioning fingers 101). The axis of the chuck 99 isdisposed in a horizontal plane and at an angle to the axes of thespindles 95 and 96 which is equal to the slope angle of the vanes 35 and36.

The fixture 98 and the chuck 99 support the rod 91 so that inreciprocation of the table 97, the horizontal axis of the rod 91 movesin a horizontal'plane 101 that is indicated in FIG. 10, and it will benoted that the spindles 95 and 96 are located at different distancesabove the plane 101 so that milling cutters of different diameters onthe respective spindles may cooperate with the rod 91 in cutting andforming the same into vane units 21.

The spindle 95 carries milling cutters 103 and 104 of conventionalconstruction that are of different diameters and which are spacedaxially as will be explained. Thus the cutter 103 is intended primarilyto form the conical surface 138 and the related lower vane surface 42,and accordingly, the cutter 103 has a side surface S42 that is remotefrom location of the fixture 98, as shown in FIG. 11, and this sidesurface S42 intersects with an outer conical surface S138 of the cutterat an included angle of 87. The width of the conical face S138 of thecutter 103 is somewhat wider than required to form the surface 138 onthe unit 21, and the opposite side of the cutter 103 is defined by aface S90.

The cutter 103 has a diameter that is determined in part by the diameterof the vane unit 21 and in part by the form and thickness to be given tothe tab 38, and in the present instance, where the diameter of the vaneunit 21 is to be inch, the diameter of the cutter 103 is about threeinches. This same general cutter diameter may be employed with othersizes of vane unit, but it should be noted that its relationship to theplane 101 must in such an instance be somewhat different as will beexplained.

As herein shown the upward spacing of the spindle 95 is such that at thelower edge of the cutter 103 the corner defined by the intersection ofthe surfaces S42 and S138 is located just slightly below the plane 101,and the purpose of this relation will be explained hereinafter.

The cutter 104 is spaced from the face S42 in an amount equal to thedistance between surfaces 41 and 42 of the vanes 35, and it has sidesurfaces 541R and S346R that are connected by an outer cylindricalsurface S146R. The purpose of the cutter 104 is to form the surface 41and to rough-out the groove 46 in the vane unit 21, and as an incidentto the foregoing, the cutter 104 also functions in the method of thisinvention to form the surfaces 38A and 383 in succession as a completedvane unit 21 is severed from the end of the rod 91. The radius of thesurface S146R of the cutter 104 is larger than the radius of the cutter103 in an amount substantially equal to the final depth of the groove 46that is to be rough milled by the cutter 104.

The spindle 96 has milling cutters 105 and 106 secured thereon in faceto face relation, and the function of these cutters is to finish millthe faces 45 and the grooves 46 of the vane units 21. The cutter 105 hasa cylindrical cutting face S45F, and the cutter 106 is of slightlylarger diameter and has side faces S346F and S41F that are connected byan outer cylindrical outing face S146F.

The radius of the cutter 105 is considerably smaller than that of thecutter 103, and the axis of the spindle 96 is therefore considerablylower than that of the spindle 95. The actual position of the spindle 96is such that the lower portion of the surface S45F of the cutter 105 isin the plane 101, and the cutter 106 projects further downwardly in anamount equal to the depth of the groove 46 in the finished vane unit 21.

In FIGS. 6 to 8 a rod 91 is shown after completion of certain of theforming operations of the present method, and the differences in form asbetween the several views will now be described in relation to themethod steps whereby the changes in form are produced. Thus in a broadsense, the rod 91 as shown in FIG. 6 has a substantially completed vaneunit 21F still rigidly and integrally in place on its forward or leftend, and this vane unit 21F is thus in condition to be severed from therod 91. As will become apparent hereinafter, such severance of the vaneunit 21F takes place as an incident to the initial or rough millingoperations that are performed in connection with the next vane unit tobe produced. Thus, after completion of the vane unit 21F to the formshown in FIG. 6, the rod 91 is advanced axially in the chuck 99, therotative relation of the rod 91 being maintained so that the plane 36 ofthe vane unit 21F is maintained in the plane 101 indicated in FIG. 6.Such advancing of the rod 91 takes place while the table is in acentered position with the extended end of the rod 91 between and spacedfrom both sets of milling cutters as indicated by the dotted circle 91in FIG. 10.

For descriptive purposes it will be assumed that when the rod has beenthus shifted, the side A of the rod 91 and the side A of the vane unit21F are located above the plane 101, and it will be noted that in FIGS.6 to 8 the sides A and B of the rod 91 have been indicated so as toclearly show the rotative or indexed relation of the rod 91.

When the rod 91 has thus been advanced endwise to its new position, itis related to the cutters 103 and 104 in the manner indicateddiagrammatically in FIG. 6, and by moving the table 97 to the left tothe extent indicated in FIG. 10 by the dotted circle 91R, the portion ofthe rod 91 adjacent the vane unit 21F is milled on its side A to theform shown in FIG. 7. Thus, comparing FIGS. 6 and 7, it will be clearthat the cutters 103 and 104 have milled away portions of side A of therod to form the vane 35A of the next vane unit 21-1, FIG. 7; to form therelated conical surface 138A; and to partially form the groove 46B forthe vane 3513. In such partial formation of the groove 4613 for the vane3513, the bottom surface of the milled cut is defined as an arcuatesurface R1463 which requires a finishing operation as will be described.

Further comparison of FIGS. 6 and 7 shows that the cutter 104 also actsto partially sever the unit 21F from the rod 91. Thus the lower tabsurface 38A is formed.

The extent of the milling operations by the cutters 103 and 104 iscarefully controlled by limiting the extent of right hand movement ofthe table 97; and this enables the form and thickness of the tab 38 tobe controlled. Thus, with the cutters 103 and 104 sized and located asabove described, and in the formation of vane units of inch diameter,the right hand stroke of the table 97 is terminated with the referencepoint 441, FIG. 7, at a distance D, FIG. 12 of inch from the verticalcenter plane of the spindle 95. This locates the intersection of lines50A and 52A, FIG. 3, substantially in the plane 36, with the line 50Aand the conical surface 138A diverging gradually from the plane 36 toproduce the desired form and thickness in the tab 38 that is to beformed on the unit 211.

When the foregoing milling step has been completed, so that the unit21-1 has the form shown in FIG. 7, the rod 91 is indexed so that theside B thereof is in the upper position shown in FIG. 8. The table 97 isthen moved to the right, FIG. 10, through the limited stroke describedso the vane 35B, FIG. 8, is formed. In this operation the cutter 104completes the cut-off operation, forming the surface 38B on the tab 38of the unit 21F and allowing this completed vane unit to drop tosuitable collecting means. The surfaces 41B, 42B, 138B, B, 346A, R45Aand R146A are also formed by the action of the cutters 103 and 104, andthe unit 21-1 is ready for cooperation with the cutters 105 and 106 tofinish cut certain of the surfaces of the vanes 35A and 35B of the unit21-1 of FIG. 8 to the relation shown in the unit 21F of FIG. 6.

Thus, with the rod 91 remaining in the same longitudinal and rotativeposition, the table 97 is operated through a stroke to the left, FIG.10, till the index point 44-1 of the rod has moved beyond the verticalcenter plane of the spindle 96, and to a position such as that indicatedat 91F in FIG. 10. As this is done, the milling cutters 105 and 106,which have the relative positions shown diagrammatically in FIG. 8, actto mill away the arcuate surfaces R45A and R146A, FIG. 8, and produce aflat surface 45A located in the plane 101, and to produce the bottomsurface 146A of the groove 46A of the unit 21-1 in form shown in theunit 21F.

After the table 97 has been returned to its center position, the rod 91is indexed to locate the side A thereof above the plane 101, while atthe same time locating the side B below the plane 161 in position tohave the finish milling operations performed thereon by the cutters 105and 106. The table 97 is then moved to the left through a finish millingstroke as above described to similarly finish the surfaces 453 and 3463.The unit 21-1 then has the same form as that of the unit 21F of FIG. 6,and the rod 91 may again be advanced longitudinally to start theformation of a succeeding vane unit.

It will be recognized that any or all of the above described millingOperations may be repeated as required to remove burrs or to attain thedesired smoothness of the milled surfaces of the finished vane units.

Where smaller vane units 521 are to be made, the cutters 103 and 165must be changed to conform with the depth and width of the grooves 46,and to conform with the distance required between the surfaces 42 and99. In general, the vertical height of the spindles 95 and 96 isdetermined in the manner described hereinabove, but with respect to thespindle 95, the position is selected so that the lowermost portion ofthe cutter 193 is located below plane 101 in an amount equal to aboutone-sixth of the diameter of the unit 521 that is to be made. Then, inthe rough milling operations, the right hand stroke of the table 97 isterminated when the dimension D, FIG. 12 is equal to about twice thediameter of the unit 521 that is being made. This causes the conicalsurface of the tab 538 to start substantially in the plane 36 and todiverge from this plane at a rate that insures proper thickness in thetab 538 of the finished vane unit.

It has been pointed out that the tab 538 of the unit 521 of FIG. 2A isrelatively long, and this added length is attained by proportionallyincreasing the spacing of the locating grooves 92 of the rod 91 fromwhich the units are made. Thus in making the units 21, the grooves 92are spaced a distance equal to of the rod diameter, while in making theunits 521, this spacing is equal to of the rod diameter. This relativeincrease appears as added length in the tab 38 or 53-8. Care must betaken of course to make sure that the cutter 103 has sufi'icient widthto mill the added width in the conical surfaces of the tab 38 or 538;and in any case, the surfaces 41A and 41B are so related to the locatinggrooves 92 that the surfaces 47A and 47B are formed at the upper ends ofthe vanes as described. This results in portions of the other side 148of the groove 92 appearing in the edges of the tab 538 adjacent to theangular lower edges of the tab 538. This is a division of applicationSerial No. 195,550, filed May 17, 1962, now Patent No. 3,104,829, issuedSeptember 24, 1963.

From the foregoing description it will be apparent that the presentinvention simplifies and reduces the cost of producing accurately formedvane units for spray nozzles, and it will also be evident that the vaneunits produced under this invention embody an integral tab whereby thevane units may be easily handled in assembly and disas sembly ofnozzles. More specificially it will be apparent that accuracy andeconomy in the production of the vane units is attained by reason of theperformance of all of the major forming operations while the unit ismaintained in the same relation to the work holder, and further, thatthe successive formation of the vane units from a length of rod stockenables simplicity in the manufacturing operations while at the sametime enabling preformed positioning grooves on the rod to serve inimparting certain desirable characteristics of form to the completedvane units.

Thus while a preferred embodiment of the invention has been illustratedherein, it is to be understood that changes and variations may be madeby those skilled in the art without departing from the spirit and scopeof the appending claims.

I claim:

1. The method of producing vane units of the character described insuccession from one end of a length of rod stock of the diameter desiredin the finished vane units, which method includes the steps ofsupporting the rod in a predetermined longitudinal and rotativeposition, forming a pair of parallel spaced milling cuts in a first sideof the rod at a predetermined angle to the rod axis to form a vane thatis perpendicular to the central plane between the first side and thesecond side of the rod and with the one of said cuts that is adjacentsaid end being narrow and of a depth such that it forms a cross grooveextending past such central plane and into the second side of the rod,and with the other milling out being relatively wide and having a bottomsurface, which at one edge of the rod and adjacent the vane is locatedsubstantially in said central plane and which diverges gradually fromsaid central plane both transversely of the rod and longitudinally ofthe rod, forming identical milling cuts in the other side of the rod atsaid predetermined angle but in reversed relation and with theoppositely sloping vanes in the same relation longitudinally of the rod,simultaneously milling the bottom of one of said cross grooves to aplane parallel to said central plane and the adjacent portion of the rodto form a surface lying in said central plane, similarly milling thebottom of the other cross groove and the adjacent portion of the rod,advancing the rod longitudinally a distance equal to the final length ofthe vane unit while maintaining the rod in the same rotative relation,and repeating the first two of the above recited sequence of millingoperations to partially form the next vane unit while severing theportion of the rod lying between said diverging surfaces to complete thefirst vane units and define a thickened tab extended from said vanes 2.In the production of vane units of the character described comprising aunitary body having upper and lower ends and said body appearinggenerally cylindrical in end elevation and having a pair of vanesdisposed on opposite sides of and perpendicular to a transverse axialplane of the body with said vanes disposed integrally joined in saidplane in the region of the axis of the body and sloping oppositely at apredetermined angle to said axis with each of said vanes in the portionsabove the region of joinder of the vanes having a groove formed thereinadjacent and parallel to the other of the vanes, and with a tab joiningsaid vanes in said plane and below said region of joinder and projectingdownwardly a substantial distance beyond said vanes, the method thatincludes the steps of supporting a rod in a predetermined longitudinaland rotative position, forming a pair of parallel spaced milling cuts ina first side of the rod at a predetermined angle to the rod axis to forma vane that is perpendicular to the central plane between the first sideand the second side of the rod and with the one of said cuts that isadjacent said end being narrow and of a depth such that it forms a crossgroove extending past such central plane and into the second side of therod, and with the other milling out being relatively wide and having abottom surface, which at one edge of the rod and adjacent the vane, islocated substantially in said central plane and which diverges graduallyfrom said central plane both transversely of the rod and longitudinallyof the rod, forming identical milling cuts in the other side of the rodat said predetermined angle but in reversed rela tion and with theoppositely sloping vanes in the same relation longitudinally of the rod,simultaneously milling the bottom of one of said cross grooves to aplane parallel to said central plane and the adjacent portion of the rodto form a surface lying in said central plane, similarly milling thebottom of the other cross groove and the adjacent portion of the rod,advancing the rod longitudinally a distance equal to the final length ofthe vane unit while maintaining the rod inthe same rotative relation,and repeating the first two of the above recited sequence of millingoperations to partially form the next vane While severing the portion ofthe rod lying between said diverging surfaces to complete the first vaneunits and define a thickened tab extended from said vanes.

3. The method of producing vane units of the character described whichincludes the steps of preforming a circular rod of the diameter desiredin the finish vane units to provide locating recesses therein at alongitudinal spacing equal to the final axial length of such units,utilizing one of such recesses to locate the rod in a work fixture,simultaneously forming across a first side of the rod and at apredetermined angle to the axis of the rod a narrow milling cut and aparallel spaced wide milling cut to form a vane disposed at said angleand with a top surface defined by a side of the narrow cut and with abotfrom surface defined by a side of the wide cut, and with the bottomsurface of the wide milling cut diverging from a central plane of therod from a location substantially in such plane at one edge of the cut,said narrow milling out being deeper than the wide cut and providing across groove with its bottom surface parallel to the bottom surface ofthe wide cut, forming identical milling cuts across the second side ofthe rod at said predetermined angle but in a reversed relation whilemaintaining the rod in the same longitudinal position, simultaneouslymilling the bottom of the one cross groove to a plane parallel to saidcentral plane and the adjacent portion of the rod above such crossgroove a surface disposed in said central plane, similarly milling thebottom of the other cross groove and the adjacent portion of the rodabove such other cross groove, advancing the rod longitudinally andutilizing the next recess to hold the rod in longitudinal position, andrepeating the first two of the above recited sequence of millingoperations to complete and sever one vane unit from the rod, and topartially form the next vane unit.

4. The method of producing vane units of character described insuccession from one end of a length of rod stock of the diameter desiredin the finished vane units, which method includes the steps ofsupporting the rod in a predetermined longitudinal and rotativeposition, forming a pair of parallel spaced milling cuts in a first sideof the rod at a predetermined angle to the rod axis to form a vane thatis perpendicular to the central plane between the first side and thesecond side of the rod and with the one of said cuts that is adjacentsaid end being narrow and of a depth such that it forms a cross grooveextending past such central plane and into the second side of the rod,and with the other milling cut being relatively wide and having a bottomsurface formed as a part of a conical surface, which at one edge of therod and adjacent the vane is located substantially in said central planeand which diverges gradually from said central plane both transverselyof the rod and longitudinally of the rod, forming identical milling cutsin the other side of the rod at said predetermined angle but in reversedrelation and with the oppositely sloping vanes in the same relationlongitudinally of the rod, simultaneously milling the bottom of one ofsaid cross grooves to a plane parallel to said central plane and theadjacent portion of the rod to form a surface lying in said centralplane, similarly milling the bottom of the other cross groove and theadjacent portion of the rod, and then severing the portion of the rodlying between said diverging surfaces to complete the vane unit anddefine a pointed tab of varying thickness extended from said vanes.

5. The method of producing vane units of the character described insuccession from one end of a length of rod stock of the diameter desiredin the finished vane units, which method includes the steps of formingannular grooves with sloping sides at points spaced along the rod atintervals equal to the length of the finished vane units, supporting therod in a predetermined rotative position and in a predeterminedlongitudinal position determined by one of said annular grooves, forminga pair of parallel spaced milling cuts in a first side of the rod at apredetermined angle to the rod axis to form a vane that is perpendicularto the central plane between the first side of the second side of therod and with said rib being defined in part by one of the sloping sidesof one of said grooves, the one of said cuts that is adjacent said endbeing narrow and of a depth such that it forms a cross groove extendingpast such central plane and into the second side of the rod, and withthe other milling cut being relatively wide and a bottom surface, whichat one edge of the rod and adjacent the vane is located substantially insaid central plane and which diverges gradually from said central planeboth transversely of the rod and longitudinally of the rod, formingidentical milling cuts in the other side of the rod at saidpredetermined angle but in reversed relation and with the oppositelysloping vanes in the same relation longitudinally of the rod,simultaneously milling the bottom of one of said cross grooves to aplane parallel to said central plane and the adjacent portion of the rodto form a surface lying in said central plane, similarly milling thebottom of the other cross groove and the adjacent portion of the rod,advancing the rod longitudinally a distance equal to the final length ofthe vane unit while maintaining the rod in the same rotative relation,and repeating the first two of the above recited sequence of millingoperations to partially form the next vane unit while severing theportion of the rod lying between said diverging surfaces to complete thefirst vane units and define a thickened tab extended from said vanes.

6. The method of producing vane units of the character described insuccession from one end of a length of rod stock of the diameter desiredin the finished vane units which method includes the steps of millingthe rod to form a pair of vanes disposed on opposite sides of andperpendicular to a transverse axial plane of the rod with said vanesintegrally joined in said plane in the region of the axis of the rod andsloping oppositely at equal angles to said axis, each of said vaneshaving parallel top and bottom surfaces, and each of said vanes in theportions above the region of joinder of the vanes having a flat sideface disposed in said plane and said fiat face having a groove formedtherein adjacent and parallel to the other of the vanes with the sidewalls of each groove parallel to the top surface of the other groove andwith the bottom surface of each groove parallel to said side face of thevane in which the groove is formed, and in such milling operationsforming a wall joining said vanes below said region of joinder and saidwall being of a thickness that increases toward the lower portions ofthe wall, and then milling through said wall parallel to and in spacedrelation to the respective vanes to sever the unit from the rod and forma tab having its lower edges defined by a pair of angularly related fiatsurfaces that are parallel to the respective bottom surfaces of thevanes.

7. The method of producing vane units of the character described insuccession from one end of a length of rod stock of the diameter desiredin the finished vane units which method includes the steps of millingthe rod to initially form a pair of vanes disposed on opposite sides ofand perpendicular to a transverse axial plane of the rod with said vanesintegrally joined in said plane in the region of the axis of the rod andsloping oppositely at equal angles to said axis, and with each of saidvanes having parallel top and bottom surfaces, milling each of saidvanes in the portions above the region of joinder of the vanes to form aflat side face thereon disposed in said plane and to form a groove ineach flat face adjacent and parallel to the other of the vanes with theside walls of each groove parallel to the top surface of the othergroove and with the bottom surface of each groove parallel to said sideface of the vane in which the groove is formed, and said initial millingforming a wall joining said vanes below said region of joinder and beingof a thickness that increases toward the lower portions of the wall, andthen milling through said Wall parallel to and in spaced relation to therespective vanes to sever the unit from the rod and form a tab havingits lower edges defined by a pair of angularly related flat surfacesthat are parallel to the respective bottom surfaces of the vanes.

8. In the production of vane units of the character described from a rodhaving the diameter desired in the finished vane units, the method whichincludes the steps of milling the end portion of such a rod to form apair of oppositely sloping vanes integrally joined at their midpoints ina central plane of the rod and joined to each other and to adjacentportions of the rod by a wall that includes such central plane, andthereafter making two separate milling cuts through said wall in spacedparallel relation to the respective vanes and spaced therefrom to severthe vane unit from the rod and form said wall as a downwardly extendedpointed tab.

9. In the production of vane units of the character described from a rodhaving the diameter desired in the finished vane units, the method whichincludes the steps of initially milling the end portion of such a rod toform a pair of oppositely sloping vanes joined at their midpoints in acentral plane of the rod and joined to each other and to adjacentportions of the rod by a wall of varying thickness that includes suchcentral plane, and thereafter as an incident to the initial milling ofthe next vane unit, making two separate milling cuts through said Wallin spaced parallel relation to the respective vanes and spaced therefromto sever the vane unit from the rod and form said wall as a downwardlyextended pointed tab.

10. In the production of vane units of the character described from arod having the diameter desired in the finished vane units, the methodwhich includes the steps of milling the end portion of such a rod toform a pair of oppositely sloping vanes joined at their midpoints in acentral plane of the rod and integrally joined to each other and toadjacent portions of the rod by a wall that includes such central planeand is defined on opposite sides by oppositely diverging segments ofconical surfaces, and thereafter making two separate milling cutsthrough said wall in spaced parallel relation to the respective vanesand spaced therefrom to sever the vane unit from the rod and form saidwall as a downwardly extended pointed tab.

11. In the production of vane units of the character described from arod having the diameter desired in the finished vane units, the methodwhich includes the steps of milling the end portion of such a rod toform a pair of oppositely sloping vanes integrally joined at theirmidpoints in a central plane of the rod and joined to each other and toadjacent portions of the rod by a Wall that includes such central planeand which is thicker where it joins the rod than it is Where it joinsthe respective vanes, and thereafter making two separate milling cutsthrough said wall in spaced parallel relation to the respective vanesand spaced therefrom to sever the vane unit from the rod and form saidwall as a downwardly extended pointed tab.

References Cited in the file of this patent UNITED STATES PATENTS

8. IN THE PRODUCTION OF VANE UNITS OF THE CHARACTER DESCRIBED FROM A RODHAVING THE DIAMETER DESIRED IN THE FINISHED VANE UNITS, THE METHOD WHICHINCLUDES THE STEPS OF MILLING THE END PORTION OF SUCH A ROD TO FORM APAIR OF OPPOSITELY SLOPING VANES INTEGRALLY JOINED AT THEIR MIDPOINTS INA CENTRAL PLANE OF THE ROD AND JOINED TO EACH OTHER AND TO ADJACENTPORTIONS OF THE ROD BY A WALL THAT INCLUDES SUCH CENTRAL PLANE, ANDTHEREAFTER MAKING TWO SEPARATE MILLING CUTS THROUGH SAID WALL IN SPACEDPARALLEL RELATION TO THE RESPECTIVE VANES AND SPACED THEREFROM TO SEVERTHE VANE UNIT FROM THE ROD AND FORM SAID WALL AS A DOWNWARDLY EXTENDEDPOINTED TAB.